Study On Acclimatization And Cultivation Of Tissue Culture Seedling Of Dendrobium Sinense

D.sinense is an endemic species in Hainan and has extremely high medicinal value.However,it has high requirements for habitats,low seed natural reproduction rate,severe habitat destruction and artificial picking,resulting in the continuous reduction of wild Dendrobium resources.Tissue culture technology can speed up the expansion of seedlings,but the cultivation techniques of tissue culture seedlings from seedlings to seedlings are immature,which restricts their industrial development.Therefore,this study explored the regulation of domestication and cultivation of D.sinense,improved the survival rate of the seedlings,and improved their cultivation by researching seedlings treatment,matrix screening,light treatment,water and fertilizer management,and planting patterns of bottle seedlings of D.sinense in vitro.technology.The research results will be of great significance to the protection and rational use of the wild resources of D.sinense.The main results of the study are as follows:（1）Tissue culture bottle seedlingsUsing different altitudes,shading degrees,and lengths of hardening,it was found that at an altitude of 204 m,the altitude was 978m,the annual average temperature was 20.7℃,July averaged 24.7℃,January average was 16.0℃,and the temperature difference between day and night was 7-15℃.The growth habit of 15-28℃is consistent;the light intensity of50%shading（average of 1560Lux per year）is more suitable for strong seedlings of D.sinense wolfberry;after four months of hardening,tissue culture seedlings can be obtained:the average stem length is 2.8cm.The average stem diameter was 0.24cm,average 3 roots per plant and root length 3-4cm.（2）Straining matrix screeningIn the initial stage of hardening,D.sinense plantlet seedlings were treated with 10 kinds of matrix pretreatment.It was found that the use of water moss as a substrate for tissue culture seedlings grew well.Further experiments showed that the use of 5cm transparent plastic cups for planting,water retention is better,and the ratio of air to water is 2.58.The dosage is 16.3g.The two-month survival rate and new bud rate were more than 50%and15%,the fresh weight increment was about 15%,and the strong seedling index and net photosynthetic rate were the highest,is 0.016 and 7.806μmol CO₂·m^-2·s^-1,a large number of new roots grew after eight months,and the root activity was 0.420mg·g·h^-1.（3）Study on conditions of seedling lightingThree shading degrees were used in the experiment,and the entire light was used as a control.Each of the 90 plants was treated.In full light,the D.sinense wolfberry seedlings quickly died within 2 weeks.When the shade was 50%,the illuminance was higher,the growth rate increased rapidly,and the strong seedling index was higher.However,the high light intensity easily sunburned the young seedlings and the leaves turned yellow and fell off.The net photosynthetic rate was 2.743μmol CO₂·m^-2·s^-1.When the shading degree was higher than 75%,the seedlings of Dendrobium hupehensis rotted easily,and the photosynthesis was low.When the illuminance was about 75%,D.sinense wolfberry The growth was normal,the light was sufficient,and the net photosynthetic rate was 5.063μmol CO₂·m^-2·s^-1,which was stable after acclimation.（4）Seedling water and fertilizer managementD.sinense seedlings are more sensitive to water and fertilizers,and the humidity of the substrate is too high to easily rot the roots,rotten stems,and serious diseases.The water content of the substrate was controlled by five kinds of water application frequency.Five fertilizer concentrations were used,and no fertilizer was used as a control,and 90 strains were treated.It was found that the frequency of water application for 2 days was used to maintain the moisture content of the matrix at around 80%,which facilitates water absorption in the root system.The survival rate and shoot bud rate of D.sinense wolfberry seedlings are relatively high,at 58%and 24%;The high-concentration fertility burned seedlings,the non-fertilized seedlings grew poorly,and the leaves were easily yellowed.The use of 25%dilution of high N fertilizers increased the fresh weight and leaf area of the young seedlings by 15%and 13%.The leaves were dark green and the strong seedlings index was The net photosynthetic rate was as high as 0.016 and 11.243μmol CO₂·m^-2·s^-1.（5）Study on Undergrowth PatternsThrough the low（204 m）,medium（978m）and high（1118 m）altitude gradients,the forest is planted at three altitudes.The altitude is low and the humidity is low.The natural environment cannot meet the survival conditions of the seedlings.Artificial cooling and humidification can be used to a certain degree.The survival rate was improved,but the effect was poor.In the high altitude habitat,the growth environment was consistent with the wild seedlings.The use of twine and a small amount of sphagnum moss could moisturize and breathe,and the survival rate was highest after 63 months,reaching 63%.And grow well.Comprehensive tests have found that at an altitude of 978 m,the average temperature is about 25℃,and the annual average humidity is above 95%.50%of shading is used to thicken the seedlings and the seedlings are thicker;the rate of seedling growth is higher;use water moss as the substrate in 5cm transparent plastic Cup planting for hardening seedlings,D.sinense seedlings survival rate is high;seedlings suitable temperature and humidity in the autumn planting,using 75%of the shading nets,two days/times the water to make the matrix water content of 80%,use a lot of diluted 2500 times the flower,the growth indexes of D.sinense seedlings were good;Combined with the optimal treatment of the above tests,the new roots and shoots were more than 8 months after the growth of D.sinense seedlings,and the root activity reached 0.413 mg·g·h^-1;Meanwhile,it was adopted in 1118m in situ.Hemp ropes and sphagnum moss are bundled to plant under the forest and the Huashi wolfberry seedlings grow better.